bug#48117: 28.0.50; Update of loaddefs.el during normal build is unreliable

[Eli Zaretskii]

> Date: Sat, 01 May 2021 08:09:42 +0000
> From: Gregory Heytings <gregory@heytings.org>
> cc: Eli Zaretskii <eliz@gnu.org>, 48117@debbugs.gnu.org
> 
> You suggested copying ldefs-boot.el onto loaddefs.el when it is more
> recent.  I'm not entirely sure, but it seems to me that forcing a
> regeneration of the loaddefs files during make whenever
> ldefs-boot.el is more recent than loaddefs.el would be a better
> solution.

Your proposal would produce marginally better results for a
significantly longer build time, so I don't think it's a net win.